(From: 18 on *General
One big change is the use of numeric index rather than string index. Before you could verb_info(obj, "index") where index was a number. Now you can directly pass the number rather than a string representing the number.
BUT, numeric index starts a 1 (and goes up to length(verbs(obj))) rather than starting at "0" like string index did. I strongly encourage you to switch to numeric index and to change your code to support numeric index rather than string index.